Which files to delete after license invalid/expired error ?

You will have to drop tables, not files, Victorious91.
You'll have to identify the tables that you suppose could be dropped and that you suppose to be big.

Then, for each table you found, go:
SELECT AUDIT('yourschema.yourtable');

you will get their audit size as a result, and you can find their audit size in :
v_catalog.user_audits.

Identify the biggest audit results for the tables you can do without, and drop them.

Hope this helps ...

Marco

Hello, thanks for the help, I have used a command to erase partitions
select drop_partition('name_of_schema.name_of_table', date) but then, when using the select get_compliance_status(); command I still receive a message that tells me that raw data size exceeds license size:
"Raw Data Size: 1.26TB +/- 0.13TB
License Size : 1.00TB
Utilization : 126%
Audit Time : 2018-10-30 00:01:53.685142+00
Node count : 1
License Node limit : 3
Compliance Status : ***** NOTICE OF LICENSE NON-COMPLIANCE *****
Continued use of this database is in violation of the current license agreement.
Maximum licensed raw data size: 1.00TB
Current raw data size: 1.26TB
License utilization: 126%
IMMEDIATE ACTION IS REQUIRED, PLEASE CONTACT VERTICA

No expiration date for a Perpetual license"

It is like the drop_partition command didn't have any effect at all...